The invention is related to a field of recording/reproducing and editing real-time information using a disc-like record carrier.
The invention relates to an apparatus for recording a real time information signal, such as a digital video signal, on a disc like record carrier, to an apparatus for editing an information signal recorded earlier on the disc like record carrier, to corresponding methods for recording/editing information, and to a reading apparatus for reading the information signal and to a record carrier. The record carrier may be of the magnetic or the optical type. An apparatus for recording a real time information signal, such as an MPEG encoded video information signal, on a record carrier is known from U.S. Pat. No. 5,579,183 (PHN 14818). The record carrier in that document is in longitudinal form.
Disc like record carriers have the advantage of a short access time. This enables the possibility of carrying out xe2x80x98simultaneousxe2x80x99 recording and reproduction of information signals on/from the record carrier. During recording and reproduction, information should be recorded on/reproduced from the record carrier such that an real time information signal can be recorded on the record carrier and xe2x80x98at the same timexe2x80x99 a real time information signal recorded earlier on the record carrier can be reproduced without any interruption.
The above references are hereby incorporated herein in whole by reference.
The invention aims at providing measures to enable the various requirements, such as the ones described above. In accordance with the invention, the apparatus for recording a real time information signal, such as a digital video signal, on a disc like record carrier, a data recording portion of which is subdivided into fixed sized fragment areas, includes:
input apparatus for receiving the information signal,
signal processing apparatus for processing the information signal into a channel signal for recording the channel signal on the disc like record carrier,
writing apparatus for writing the channel signal on the record carrier, the signal processing apparatus being adapted to convert the information signal into blocks of information of the channel signal, the writing being adapted to write a block of information of the channel signal in a fragment area on the record carrier, and wherein the signal processing is further adapted to convert the information signal into the blocks of information of the channel signal, such that the size of the blocks of information can be variable and satisfies the following relationship:
SFA/2xe2x89xa6size of a block of the channel signalxe2x89xa6SFA,
where SFA equals the fixed size of the fragment area.
Further, the apparatus for editing a real time information signal, such as a digital video signal, recorded in an earlier recording step on a disc like record carrier, a data recording portion of which is subdivided into fixed sized fragment areas, the information signal being converted into a channel signal prior to recording and subsequently recorded on the record carrier, such that blocks of information of the channel signal are recorded in corresponding fragment areas on the record carrier, includes:
input apparatus for receiving an exit position in a first information signal recorded on the record carrier and for receiving an entry position in a second information signal, which may be the first information signal, recorded on the record carrier,
apparatus for storing information relating to the said exit and entry position,
bridging block generating apparatus for generating at least one bridging block of information, which bridging block of information includes information from at least one of the first and second information signals, which information is located before the exit position in the first information signal and/or after the entry position in the second information signal, and where the size of a bridging block of information can be variable and satisfies the requirement:
SFA/2xe2x89xa6size of a bridging block of informationxe2x89xa6SFA,
where SFA equals the fixed size of the fragment areas,
writing apparatus for writing the at least one bridging block of information into a corresponding fragment area, and
apparatus for reproducing the edited stream of information from said record carrier.
Further, the apparatus for reading a real time information signal, such as a digital video signal, from a disc like record carrier, the information signal being recorded in channel encoded form in a data recording portion of the record carrier, the data recording portion being subdivided into fixed size fragment area, blocks of information of the channel encoded information signal being recorded in corresponding fragment areas, the size of the blocks of information can be variable and satisfy the following relationship:
SFA/2xe2x89xa6size of a block of information of the channel signalxe2x89xa6SFA,
where SFA equals the fixed size of the fragment areas, the apparatus includes:
apparatus for reading the channel signal from the record carrier,
signal processing apparatus for processing the blocks of information of variable size and read from the fragment areas into portions of the information signal,
apparatus for outputting the information signal.
A further advantageous embodiment is characterized in that the blocks of information of a consecutive sequence satisfy alternately the following relationships:
SFA/2xe2x89xa6size of a block of the channel signalxe2x89xa6SFA
and
size of a block of the channel signed=SFA.
This leads to either a more efficient occupation of space or eases the requirements of an apparatus. Another advantageous embodiment with the same advantages as above is characterized in that the blocks of information of a consecutive sequence satisfy the following relationship:
2 SFA/3xe2x89xa6size of a block of the channel signalxe2x89xa6SFA.
These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments hereafter in the figure description,